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61.
Kerfeld CA Sawaya MR Brahmandam V Cascio D Ho KK Trevithick-Sutton CC Krogmann DW Yeates TO 《Structure (London, England : 1993)》2003,11(1):55-65
Carotenoids undergo a wide range of photochemical reactions in animal, plant, and microbial systems. In photosynthetic organisms, in addition to light harvesting, they perform an essential role in protecting against light-induced damage by quenching singlet oxygen, superoxide anion radicals, or triplet-state chlorophyll. We have determined the crystal structure of a water-soluble orange carotenoid protein (OCP) isolated from the cyanobacterium Arthrospira maxima at a resolution of 2.1 A. OCP forms a homodimer with one carotenoid molecule per monomer. The carotenoid binding site is lined by a striking number of methionine residues. The structure reveals several possible ways in which the protein environment influences the spectral properties of the pigment and provides insight into how the OCP carries out its putative functions in photoprotection. 相似文献
62.
A novel one-pot synthesis of imidazo[1,2-c]pyrimido[5,4-e]pyrimidinones (2), tetraazaacenaphthene-3,6-diones (4), tetarazaphenalene-1,7-dione (4d) is delineated from the reaction of cyclic ketene aminal (1) and alkyl or aryl isothiocyanate through tandem addition-cyclization reactions. However, reaction of ketene aminal (1a) with alkyl isothiocyanate only yielded angularly cyclized product 5 which did not react further to yield 6. The structure of 2c and 4d was ascertained by single crystal X-ray diffraction analysis which demonstrated a network of various inter- and intramolecular interactions, responsible for the stability and packing of the molecules in the crystalline state. Some of the compounds (2a--h) were screened for hepatoprotective activity but only 2a was found most effective. 相似文献
63.
Vishnu Mohanan Catherine Leimkuhler Grimes 《The Journal of biological chemistry》2014,289(27):18987-18998
Microbes are detected by the pathogen-associated molecular patterns through specific host pattern recognition receptors. Nucleotide-binding oligomerization domain-containing protein 2 (NOD2) is an intracellular pattern recognition receptor that recognizes fragments of the bacterial cell wall. NOD2 is important to human biology; when it is mutated it loses the ability to respond properly to bacterial cell wall fragments. To determine the mechanisms of misactivation in the NOD2 Crohn mutants, we developed a cell-based system to screen for protein-protein interactors of NOD2. We identified heat shock protein 70 (HSP70) as a protein interactor of both wild type and Crohn mutant NOD2. HSP70 has previously been linked to inflammation, especially in the regulation of anti-inflammatory molecules. Induced HSP70 expression in cells increased the response of NOD2 to bacterial cell wall fragments. In addition, an HSP70 inhibitor, KNK437, was capable of decreasing NOD2-mediated NF-κB activation in response to bacterial cell wall stimulation. We found HSP70 to regulate the half-life of NOD2, as increasing the HSP70 level in cells increased the half-life of NOD2, and down-regulating HSP70 decreased the half-life of NOD2. The expression levels of the Crohn-associated NOD2 variants were less compared with wild type. The overexpression of HSP70 significantly increased NOD2 levels as well as the signaling capacity of the mutants. Thus, our study shows that restoring the stability of the NOD2 Crohn mutants is sufficient for rescuing the ability of these mutations to signal the presence of a bacterial cell wall ligand. 相似文献
64.
Cryptococcus gattii is unique among human pathogenic fungi with specialized ecological niche on trees. Since leaves concentrate CO2, we investigated the role of this gaseous molecule in C. gattii biology and virulence. We focused on the genetic analyses of β-carbonic anhydrase (β-CA) encoded by C. gattii CAN1 and CAN2 as later is critical for CO2 sensing in a closely related pathogen C. neoformans. High CO2 conditions induced robust development of monokaryotic hyphae and spores in C. gattii. Conversely, high CO2 completely repressed hyphae development in sexual mating. Both CAN1 and CAN2 were dispensable for CO2 induced morphogenetic transitions. However, C. gattii CAN2 was essential for growth in ambient air similar to its reported role in C. neoformans. Both can1 and can2 mutants retained full pathogenic potential in vitro and in vivo. These results provide insight into C. gattii adaptation for arboreal growth and production of infectious propagules by β-CA independent mechanism(s). 相似文献
65.
Vishnu Chaturvedi Jean-Philippe Bouchara Ferry Hagen Ana Alastruey-Izquierdo Hamid Badali Anamelia Lorenzetti Bocca Jose F. Cano-Lira Cunwei Cao Sudha Chaturvedi Sanjay H. Chotirmall Anne D. van Diepeningen Jean-Pierre Gangneux Jesus Guinea Sybren de Hoog Macit Ilkit Rui Kano Weida Liu Nilce M. Martinez-Rossi Marcia de Souza Carvalho Melhem Mario Augusto Ono Yuping Ran Stephane Ranque Celia Maria de Almeida Soares Takashi Sugita Philip A. Thomas Anna Vecchiarelli Nancy L. Wengenack Patrick C. Y. Woo Jianping Xu Rosely M. Zancope-Oliveira 《Mycopathologia》2018,183(6):859-877
Mycopathologia was founded in 1938 to ‘diffuse the understanding of fungal diseases in man and animals among mycologists.’ This was an important mission considering that pathogenic fungi for humans and animals represent a tiny minority of the estimated 1.5–5 million fungal inhabitants on Earth. These pathogens have diverged from the usual saprotrophic lifestyles of most fungi to colonize and infect humans and animals. Medical and veterinary mycology is the subdiscipline of microbiology that dwells into the mysteries of parasitic, fungal lifestyles. Among the oldest continuing scientific publications on the subject, Mycopathologia had its share of ‘classic papers’ since the first issue was published in 1938. An analysis of the eight decades of notable contributions reveals many facets of host–pathogen interactions among 183 volumes comprising about 6885 articles. We have analyzed the impact and relevance of this body of work using a combination of citation tools (Google Scholar and Scopus) since no single citation metric gives an inclusive perspective. Among the highly cited Mycopathologia publications, those on experimental mycology accounted for the major part of the articles (36%), followed by diagnostic mycology (16%), ecology and epidemiology (15%), clinical mycology (14%), taxonomy and classification (10%), and veterinary mycology (9%). The first classic publication, collecting nearly 200 citations, appeared in 1957, while two articles published in 2010 received nearly 150 citations each, which is notable for a journal covering a highly specialized field of study. An empirical analysis of the publication trends suggests continuing interests in novel diagnostics, fungal pathogenesis, review of clinical diseases especially with relevance to the laboratory scientists, taxonomy and classification of fungal pathogens, fungal infections and carriage in pets and wildlife, and changing ecology and epidemiology of fungal diseases around the globe. We anticipate that emerging and re-emerging fungal pathogens will continue to cause significant health burden in the coming decades. It remains vital that scientists and physicians continue to collaborate by learning each other’s language for the study of fungal diseases, and Mycopathologia will strive to be their partner in this increasingly important endeavor to its 100th anniversary in 2038 and beyond. 相似文献
66.
Akshara George M. L. Jeeva Vishnu S. Nath G. L. Sreelatha M. G. Sujina 《Archives Of Phytopathology And Plant Protection》2018,51(5-6):241-251
Genomic DNA extraction protocol with relatively high quantity and purity is prerequisite for the successful molecular identification and characterisation of plant pathogens. Conventional DNA extraction methods are often time-consuming and yield only very poor quantity of genomic DNA for samples with higher mycelial age. In our laboratory, we have aimed at establishing an efficient DNA isolation procedure, exclusively for the oomycete pathogen Phytophthora colocasiae causing serious leaf blight disease in taro. For this a phenol free protocol was adopted, which involves SDS/Proteinase K-based inactivation of protein contaminants, extraction of nucleic acids using chloroform: isoamyl alcohol and later precipitation of genomic DNA using isopropanol and sodium acetate. The purity of the isolated DNA was analysed by A260/280 and A260/230 spectrophotometric readings and confirmed by restriction digestion with restriction enzyme Eco RI. In this study, a comparative assessment was done with CTAB method and the commercial genomic DNA purification kit (Thermo Fisher Scientific, Fermentas, EU). The extracted DNA was found to be suitable for further downstream applications like ITS amplification of the rDNA ITS region and PCR amplification with species-specific primers. 相似文献
67.
Vishnu Balaji Wojciech Pokrzywa Thorsten Hoppe 《BioEssays : news and reviews in molecular, cellular and developmental biology》2018,40(5)
The insulin/insulin‐like growth factor‐1 (IGF‐1) signaling (IIS) pathway is a pivotal genetic program regulating cell growth, tissue development, metabolic physiology, and longevity of multicellular organisms. IIS integrates a fine‐tuned cascade of signaling events induced by insulin/IGF‐1, which is precisely controlled by post‐translational modifications. The ubiquitin/proteasome‐system (UPS) influences the functionality of IIS through inducible ubiquitylation pathways that regulate internalization of the insulin/IGF‐1 receptor, the stability of downstream insulin/IGF‐1 signaling targets, and activity of nuclear receptors for control of gene expression. An age‐related decline in UPS activity is often associated with an impairment of IIS, contributing to pathologies such as cancer, diabetes, cardiovascular, and neurodegenerative disorders. Recent findings identified a key role of diverse ubiquitin modifications in insulin signaling decisions, which governs dynamic adaption upon environmental and physiological changes. In this review, we discuss the mutual crosstalk between ubiquitin and insulin signaling pathways in the context of cellular and organismal homeostasis. 相似文献
68.
Kaushal Kumar Singh Radhey Shyam Prafullachandra Vishnu Sane 《Photosynthesis research》1996,49(1):11-20
Effect of quality, quantity and minimum duration of light on the process of recovery was investigated in the photoinhibited cells of the green alga Chlamydomonas reinhardtii. Complete and rapid reactivation of photosynthesis took place in diffuse white light of 25 mol m–2 s–1. The recovery was partial (< 10%) in the dark. Far red (725 nm), red (660 nm) and blue light (480 nm) in the range of 10 to 75 mol m–2 s–1 did not enhance the process of reactivation. Photoinhibited cells incubated in dark for 15 min when exposed for 5 min to diffuse light (25 mol m–2 s–1) showed complete reactivation. Even exposure of 15 min dark incubated photoinhibited cells to photoinhibitory light (2500 mol m–2 s–1) for 5 s fully regained the photosynthesis. The study indicated a very precise and triggering effect of light in the process of reactivation. The dark respiratory inhibitor KCN and uncouplers FCCP and CCCP increased the susceptibility of C. reinhardtii to photoinhibition and also prevented photoinhibited cells to reactivate fully even after longer period of incubation under suitable reactivating conditions. Of the various possibilities envisaged to assign the role of dark respiration in recovery process, supply of ATP by mitochondrial respiration appeared sound and pertinent.Abbreviations CCCP-
carbonyl cyanide m-chlorophenylhydrazone
- D1-
32 kDa protein of PS II reaction center
- FCCP-
carbonyl cyanide p-(trifluoromethoxy)phenylhydrazone
- KCN-
potassium cyanide
- PBQ-
phenyl-p-benzoquinone
- PFD-
photon flux density
- SHAM-
salicylhydroxamic acid
NBRI Research Publication No. 431. 相似文献
69.
InMazus pumilus, all the floral appendages are initiated in acropetal sequence in the second cell layer (except stamens) of the floral primordium
by periclinal divisions. The actinomorphic calyx tube is formed due to zonal growth. The zygomorphy in corolla is evident
from the inception of petal primordia which arise sequentially as independent units in order of one anterior, a pair of anterio-lateral
followed by a pair of posterio-lateral. Later these primordia exhibit differential growth because of which zygomorphy becomes
more pronounced. The upper corolla tube is formed by interprimordial growth and lower corolla tube by zonal growth. Stamens
are initiated in the third layer of the floral apex. Unlike sepals and petals, in the development of stamens (4) underlying
cells of corpus also contribute. Posterior stamen is absent. The stamens become epipetalous because of interprimordial and
zonal growth in the common region below the bases of petals as well as stamens. The two carpel primordia arise as crescent
shaped structures which become continuous due to interprimordial growth. The ovary is formed by a ring of zonal meristem.
The style develops later between stigma and ovary because of intercalary growth. The residual apex grows vertically along
with the ovary and forms the septum of the ovary. All the floral appendages exhibit similar pattern of histogenesis and early
growth suggesting thereby the appendicular nature of these appendages. 相似文献
70.
High-quality RNA from cells isolated by laser capture microdissection 总被引:11,自引:0,他引:11
Mikulowska-Mennis A Taylor TB Vishnu P Michie SA Raja R Horner N Kunitake ST 《BioTechniques》2002,33(1):176-179
Laser capture microdissection (LCM) provides a rapid and simple method for procuring homogeneous populations of cells. However, reproducible isolation of intact RNAfrom these cells can be problematic; the sample may deteriorate before or during sectioning, RNA may degrade during slide staining and LCM, and inadequate extraction and isolation methods may lead to poor recovery. Our report describes an optimized protocol for preparation of frozen sections for LCM using the HistoGene Frozen Section Staining Kit. This slide preparation method is combined with the PicoPure RNA Isolation Kitfor extraction and isolation of RNA from low numbers of microdissected cells. The procedure is easy to perform, rapid, and reproducible. Our results show that the RNA isolated from the LCM samples prepared according to our protocol is of high quality. The RNA maintains its integrity as shown by RT-PCR detection of genes of different abundance levels and by electrophoretic analysis of ribosomal RNA. RNA obtained by this method has also been used to synthesize probes for interrogating cDNA microarray analyses to study expression levels of thousands of genes from LCM samples. 相似文献